With freewheels of this type it is known that, during idling, the retainer ring revolves together with the freewheel outer ring, while the freewheel inner ring stands still. The clamping members are thereby pressed outward by the centrifugal force acting upon them, swung in the disengaging direction and thereby lifted off from the freewheel inside ring. The clamping member center of gravity in relation to the clamping member axis of rotation is thereby so displaced in the circumferential direction that the center of gravity moves outward upon pivoting in the disengagement direction. Since the retainer ring rotates synchronously with the freewheel outer ring, any abrasion during idling is eliminated as soon as the number of revolutions required for the centrifugal force takeoff is exceeded. This has considerable significance because even minor material wear and tear on the clamping member can lead to malfunctions as a consequence of uneven engagement, and finally to a breakdown of the freewheel with dangerous consequences for the maintenance personnel.
Allowing the clamping member to takeoff from the outer ring instead of the inner ring, while idling, is known from DE-A 20 04 457, from which the present invention proceeds. This alternative is required when the freewheel inner ring rotates in idling operation while the outer ring stands still. For this, the center of gravity of the clamping member must be shifted toward the clamping member tilt axis, such that the swinging movement in the disengaging direction leads to a takeoff of the clamping member from the freewheel outer ring. Since the bracing of the clamping members against the action of centrifugal force in this case can no longer take place by the outer ring, they are braced in the known case against a concentric prop ring, which stands in friction-locking contact with the freewheel inner ring. This prop ring can also consist of inwardly jutting bends of the two edge rings of the retainer ring.
A disadvantage with this known construction is the fact that the clamping members are not guided in the circumferential direction. They can thereby bump into one another and mutually disturb each other in their tilting movement. This can lead to an uneven grip of individual clamping members upon engaging, especially in sudden torque thrusts, possibly upon starting up from idling, from which undesirable locally high stresses result which endanger the function of the freewheel.
For eliminating these disadvantages, it has become known from DE-A 31 51 727 to guide the clamping members in the circumferential direction by mounting each of them in a clamp. Each clamp has stamped-on flaps on both axial ends, which project into corresponding openings of the edge rings and bend over behind these. In this way, the clamps hold not only the clamping members but also the two edge rings of the retainer ring.
The advantage resulting from this solution, of being able to cover varying freewheel diameters with clamping members and clamps remaining the same and only having to adapt the edge rings to the respective diameter, is, however, bought at the price of a relatively high manufacturing expense.